Latin name: Elaeis guineensis
Source material: Pollen
Common names: Oil palm, African oil palm, Palma Africana
Synonym: Elaeis melanococca
Elaeis is a genus consisting of only 2 species of Palms. Elaeis guineensis originally occurred in Africa, and Elaeis oleifera in Central and South America. The trees are now cultivated throughout the tropics and sometimes grown as ornamentals in other parts of the world, in particular in southern Florida. Palm oil from this genus is the second most frequently consumed vegetable oil in the world.
The Oil palm can reach 25 m in height. Its trunk is stout, erect and ringed. The feathery, fibrous fronds are green and up to 5 m long and 20 cm wide, saw-toothed and broadened at the base, each with 100-150 pairs of leaflets. The plant is monoecious (having male and female inflorescences in separate clusters, but on same tree). The male flowers occur on short, furry branches 10-15 cm long. Female flowers, and consequently fruits, occur in clusters of 200-300. Fruits are plum-like, oblong in shape, 3.5 cm long and about 2 cm wide.
Both species of Oil palm grow in open situations, such as along streams, in swamps and on savannahs. They are also in extensive commercial cultivation.
Palm kernel oil is used for the manufacture of soaps and candles, and more recently of detergents, margarine, cooking fats, mayonnaise, sweets and baked goods. It is an important industrial lubricant.
The pressed cake, after extraction of the oil from the kernels, is used as livestock feed. The leaves and other parts of the plant are used in thatching, building, mulching and manuring. The ash is sometimes used in soap-making.
The following allergens have been characterised:
- Ela g Profilin (1).
- Ela g Bd 31kD (2-3).
Ela g Bd 31kD was strongly recognised by IgE in 3 Oil palm pollinosis patients, weakly in 1, and not at all in 2 (2).
An extensive cross-reactivity among the different individual species of the genus could be expected, as well as among members of the family (4).
Oil palm pollen may commonly induce symptoms of allergic rhinitis and asthma in sensitised individuals, especially in Malaysia and Singapore (5-6).
In an aerobiologic survey of Singapore, crude extracts of 23 major spore (fungal and fern) and pollen types were assessed in 231 patients with asthma and/or allergic rhinitis and 76 healthy controls by skin prick test and total and specific IgE tests. Extracts of Oil palm pollen were observed to have the highest frequency of positive reactions (40%). Positive responses to these extracts correlated with total serum IgE levels of the subjects and were significantly associated with the presence of atopic disease (2).
A total of 107 patients with allergic rhinitis and/or asthma in Jakarta, Indonesia, were evaluated via skin prick test: 32 children and 75 adolescents and adults; there were also 20 normal control volunteers. Sensitisation to Palm oil pollen was demonstrated in 22.43%. No difference was noted between children and adults in the allergic group (3).
A study of the prevalence of allergen sensitisation among asthmatics in Thailand (84 paediatric, 71 adult asthmatics) found that sensitisation to Oil palm pollen in child and adult asthmatics was 8.3% and 5.6%, respectively (7).
Allergy to the fruit of Oil palm is possible. In a study that identified sensitivity to a Coconut (Cocos nucifera) 7S globulin in 2 Coconut-allergic patients, the greatest similarity was to a protein from Oil palm, a species also belonging to the Arecaceae family. Cross-reactivity among Coconut, Walnut, and Hazelnut was demonstrated by inhibition studies in patient 2 (8).
Compiled by Dr Harris Steinman, email@example.com.
Chew F.T., Wang D.L., Shang H.S., Lee B.W.
Identification and cloning of profilin homolog allergen PF1 from Elaeis guineensis Jacq. http://www.uniprot.org/uniprot/A1KXJ9 2003;May
Kimura Y, Maeda M, Kimupa M, Lai OM, Tan SH, Hon SM, Chew FT. Purification and characterization of 31-kDa palm pollen glycoprotein (Ela g Bd 31 K), which is recognized by IgE from palm pollinosis patients. Biosci Biotechnol Biochem 2002;66(4):820-7
Kimura Y, Yoshiie T, Kit WK, Maeda M, Kimura M, Tan SH. Structural features of N-glycans linked to glycoproteins from oil palm pollen, an allergenic pollen*. Biosci Biotechnol Biochem 2003;67(10):2232-9
Yman L. Botanical relations and immuno-logical cross-reactions in pollen allergy. 2nd ed. Pharmacia Diagnostics AB. Uppsala. Sweden. 1982: ISBN 91-970475-09
Chew FT, Lim SH, Shang HS, Dahlia MD,
Goh DY, Lee BW, Tan HT, Tan TK. Evaluation of the allergenicity of tropical pollen and airborne spores in Singapore.
Baratawidjaja IR, Baratawidjaja PP, Darwis A,
Soo-Hwee L, Fook-Tim C, Bee-Wah L, Baratawidjaja KG. Prevalence of allergic sensitization to regional inhalants among allergic patients in Jakarta, Indonesia. Asian Pac J Allergy Immunol 1999;17(1):9-12
Daengsuwan T, Lee BW, Visitsuntorn N,
Charoenratanakul S, Ruangrak S, Jirapongsananuruk O, Vichyanond P. Allergen sensitization to aeroallergens including Blomia tropicalis among adult and childhood asthmatics in Thailand. Asian Pac J Allergy Immunol 2003;21(4):199-204
Benito C, Gonzalez-Mancebo E, de D, Tolon RM,
Fernandez-Rivas M. Identification of a 7S globulin as a novel coconut allergen. Ann Allergy Asthma Immunol 2007;98(6):580-4